In parallel to arteriosclerosis, enhanced cholangiocellular VCAM-1 expression was recently demonstrated in multidrug resistance gene (Mdr2/Abcb4) knockout mice (Mdr2-/-), a well characterized mouse model that closely mirrors the macroscopic and microscopic pathology of PSC [8,11]. The gene discussed is ABCB4; the disease is arteriosclerosis disorder.